dart2js: run dartfmt on tests

tests/compiler/dart2js_extra/21166_test.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Regression test for http://dartbug.com/21166/
 // Fails when compiling with --checked.
 
 var a = [];
 
 void doStuff() {
-  if (a.length) { // This triggers a TypeConversion to bool in checked mode.
+  if (a.length) {
+    // This triggers a TypeConversion to bool in checked mode.
     var element = a[0]; // This triggers a bounds check but a.length will have
-    a.remove(element);  // type [empty].
+    a.remove(element); // type [empty].
   }
 }
 
 main() {
   a.add(1);
   a.add(2);
   try {
     doStuff(); // This is expected to fail but not crash the compiler.
   } catch (_) {}
 }
-
-